Plastic containers have been used as a replacement for glass or metal containers in the packaging of beverages for several decades. The most common plastic used in making beverage containers today is polyethylene terephthalate (PET). Containers made of PET are transparent, thin walled, and have the ability to maintain their shape by withstanding the force exerted on the walls of the container by their contents. PET resins are also reasonably priced and easy to process. PET bottles are generally made by a process that includes the blow-molding of plastic preforms which have been made by injection molding of the PET resin.
Advantages of plastic packaging include lighter weight and decreased breakage as compared to glass, and lower costs overall when taking both production and transportation into account. Although plastic packaging is lighter in weight than glass, there is still great interest in creating the lightest possible plastic packaging so as to maximize the cost savings in both transportation and manufacturing by making and using containers that contain less plastic.
FIG. 1 illustrates a lower perspective view of an exemplary container 100 typically used for storing liquid contents, and particularly carbonated contents. The container 100 comprises a base 104 that extends up to a grip portion 108. In some embodiments, the base 104 may be of the petaloid variety, although other configurations of the base may be incorporated into the container 100, without limitation. The grip portion 108 comprises a generally smooth, cylindrical portion of the container 100 suitable for affixing a label, as well as providing a location for grasping the container. In some embodiments, the grip portion 108 may comprise one or more sidewall ribs that generally may vary in depth, and may swirl or angulate around the grip portion 108. Additional configurations of the grip portion 108 are disclosed in U.S. Patent Application, entitled “Plastic Container with Strapped Base,” filed on Jan. 16, 2014, having application Ser. No. 14/157,400, the entirety of which application is incorporated by reference herein.
In the illustrated embodiment, the grip portion 108 transitions into a shoulder 124, which connects to a bell 128. Although the bell 128 illustrated in FIG. 1 is smooth and generally unornamented, in other embodiments the bell may include design features, such as, by way of non-limiting example, a plurality of scallops. The bell 128 connects to a neck 136, which connects to a finish 140. As shown in FIG. 1, the bell 128 comprises a diameter that generally decreases as the bell 128 extends upward from the shoulder 124 to the neck 136 and the finish 140. The finish 140 may be adapted to receive a closure to seal contents in the container 100, such as, by way of non-limiting example, a container cap 164 or a bottle cap. The finish 140 generally defines an opening that leads to an interior of the container 100 for containing a beverage, or other contents. The finish 140 may be of the Carbonated Soft Drink (CSD) variety, or may be configured to receive container caps suitable for sealing noncarbonated contents within the interior of the container 100.
FIG. 2 illustrates an upper perspective view of an exemplary finish 140 that is configured to rotatably engage with the container cap 164 so as to seal contents within the interior of the container 100. The finish 140 comprises a cylindrical body 148 that includes a peripheral portion with a first edge 152 and a second edge 156 disposed at opposite ends. The first edge 152 defines an opening 160 and is configured to receive a plug seal 168, as shown in FIG. 3 within the container cap 164, as disclosed herein. The second edge 156 is configured to receive the neck 136 of the container 100, as shown in FIGS. 1 and 2, such that the opening 160 is in fluid communication with the interior of the container 100 once the finish 140 is installed thereon.
An exterior of the cylindrical body 148 comprises one or more threads 172 that are configured to rotatably engage with one or more threads 176 of the container cap 164. An engagement of the threads 172 of the finish 140 with the threads 176 of the container cap 164 is best shown in FIG. 3. As shown in FIG. 2, a plurality of gaps 174 may be disposed in the threads 172 and positioned uniformly around the perimeter of the cylindrical body 148. Preferably, the gaps 174 of adjacent threads 172 are vertically aligned so as to form channels 178 extending longitudinally along the finish 140. The channels 178 advantageously operate to relieve pressure within the container 100 when the container cap 164 is loosened. As will be appreciated, the channels 178 may provide a direct route for gases escaping the interior of the container 100, rather than the gases being forced to travel around the finish between adjacent threads 172.
In the embodiment illustrated in FIG. 1, the container cap 164 comprises a tamper evidence band 166 that is disposed around the perimeter of the finish 140. The tamper evidence band 166 is attached to the container cap 164 by a multiplicity of thin connections. A neck ring 170, best shown in FIG. 2, generally comprises a rounded upper portion configured to facilitate passing the tamper evidence band 166 over the neck ring 170 during assembly of the cap 164 onto the container 100. A flat lower portion of the neck ring 170 retains the tamper evidence band 166 positioned below the neck ring 170 during loosening of the cap. For example, when an end-user later loosens the contain cap 164, the neck ring 170 retains the tamper evidence band 166 positioned below the neck ring 170, breaking the thin connections between tamper evidence band and the cap 164. The tamper evidence band 166 remains positioned below the neck ring 170 after the container cap 164 is removed from the container 100. Thus, the tamper evidence band 166 and neck ring 170 cooperate to indicate to the end-user that the cap 164 has not been previously loosened after being installed by the manufacturer.
A drawback to conventional tamper evidence bands, such as the band 166, is that it may be difficult for an end-user to directly observe whether or not the container cap 164 has been previously separated from the tamper evidence band 166 and removed from the container. Consequently, the container cap 164 may be separated from the tamper evidence band 166, the container 100 may be refilled, and another container cap may be installed onto the container, giving little visual indication to the end-user that the container 100 has been reused. One solution to this problem has been to make the finish 140 taller so that the second edge 156 is lower, allowing the tamper evidence band 166 to drop once the container cap 164 has been separated from the container 100. Unfortunately, making the finish 140 taller generally adds unwanted weight to the container 100. Moreover, in some instances the tamper evidence band 166 may be removed from the finish 140 and a new container cap 164 may be placed onto the container 100, leaving a consumer with essentially no evidence that the container 100 had been previous opened.
Another drawback to conventional tamper evidence bands 166 is that the container cap 164 generally must be screwed onto the finish 140 by way of a chuck. A solution to this drawback has been to merely push the container cap onto the finish 140, such that the threads 176 snap onto the threads 172 and the tamper evidence band 166 is retained below the neck ring 170. A drawback to pushing the container cap 164 onto the finish 140 is that snapping the threads 172, 176 together typically requires the threads 172, 176 to be short enough to allow internal pressure within the container to push the container cap off the finish. As will be recognized, such an internal pressure may be due to heat, dissolved gas, or even due to a consumer squeezing the bottle.
What is needed, therefore, is a tamper evidence bridge that provides a visible indication about whether or not a manufacturer installed container cap has been previously removed. Further, there is a need for a reduction of turbulence in liquid contents during pushing the container cap onto the finish during manufacturing as well as a design that resists being pushed off the bottle by internal pressure.